This action-research project explores the utility of a multifactorial approach to understanding and preventing the development of psychopathology in early adolescence. The study focuses on three widely replicated risk factors: life events, stressful family environments, and poor peer friendships. Emphasis is placed on the difficult, but critical task of identifying coping processes leading to resilience or dysfunction, and translating these findings into preventive interventions. A prospective, short-term longitudinal study is proposed of the transition to high school (a major developmental event) among adolescents who vary in terms of family stress and peer friendships. A preventive intervention among high-risk adolescents will be implemented, evaluated, and replicated. The intervention involves the development of a school-based, nonstigmatizing social setting for developing competence and increasing social support. Evaluation involves the use of a repeated measures design with random assignment of matched groups of high-risk adolescents to intervention or nonintervention conditions. The research involves the use of a multimethod, multimeasure assessment approach, including the use of: structured diagnostic interviews to assess specific mental health disorders and dysfunctions, self-report measures of subsyndromal dysfunctions and other symptomatology, and peer ratings of adjustment; measures of life events, family and school environments, coping behavior, and social support; and behavioral coding of friendship interactions.